Background: Although large waist–height ratio (WHtR) is associated with increased cardiometabolic risks, its ethnic difference in adolescents is unclear. This study aimed to investigate the ethnic differences in cardiometabolic risk across the WHtR spectrum among adolescents.Methods: Data for this cross-sectional study were obtained from National Health and Nutrition Examination Surveys (2001–2014), and a total of 7385 participants aged 12–17 years were involved. The associations between WHtR and cardiometabolic outcomes measures were assessed with fractional polynomial regression and logistic regression models.Results: The risk of all cardiometabolic risk factors increased with increasing WHtR. However, significant ethnic differences in risk of adverse cardiometabolic outcomes were observed across the WHtR spectrum. At a WHtR of 0.5, compared with non Hispanic (NH) whites, NH blacks revealed higher risks of elevated HbA1c, insulin resistance and hypertension, and lower risks of abnormal lipid profile, high glucose, elevated uric acid, and metabolic syndrome, with odds ratios (ORs) ranging from 1.36 (95% confidence interval: 1.17, 1.55) to 4.81 (2.94, 6.67) and 0.33 (0.23, 0.43) to 0.72 (0.53, 0.91), respectively. Additionally, significant differences in risks of abnormal lipid profile, elevated uric acid, abnormal glucose and insulin resistance were observed between Mexican Americans and NH whites as well.Conclusions: Significant ethnic disparities in cardiometabolic risk were observed in adolescents across the WHtR spectrum. Our findings pointed to opportunities to target particular cardiometabolic risk factors in specific ethnicities, and suggested the development of ethnicity-specific WHtR thresholds.